Foam Pumping System

Description

The SUREX foam pumping system incorporatesa UL Listed and FM Approved positive displacement bronze rotary gear foam pumpcapable of dry operation. The balance valve, pressure relief valve, and pipingproducts are all 316 Stainless Steel as standard materials. A UL Listed/FM ApprovedNEMA 2 foam pump controller, mounted and wired on the skid, is included.

The SUREX balanced pressure proportioning skid,is a complete foam pumping system, equipped with supply and discharge piping(excluding the foam supply piping and foam return piping to the foam tank), auxiliaryflushing connections, concentrate discharge check valve, pressure sustaining valve,pressure relief valve, concentrate supply strainer, foam pump and pump controller.The rotary gear pump is of all bronzeconstruction to withstand the corrosive atmosphere that exists with AFFF andAR-AFFF concentrates. The double pair gears construction of the pump allows it torun dry without damage to the pump.

The SUREX skid is to be used anywhere afoam system that utilizes positive pressure proportioning (ILBP) isdesired or necessary. The SUREX skid can supply single or multiple foam systemswith balanced pressure proportioning.

Application

The SUREX skid foam pumping systems arefoam concentrate delivery devices. SUREX skid foam systems are a critical partof a low or high expansion foam system which includes the followingapplications: aircraft hangars, petrol-chemical facilities, flammable andcombustible liquid warehouses, tank farms, facilities for bulk storage of flammableor combustible liquids, offshore FPSO and shipboard applications and manymilitary installations. The SUREX skid systems can supply foam concentrate toconcentrate injection piping run above or below ground.

Selection

The SUREX balanced pressure proportioning systemis available in five basic sizes, available with four standard foam dischargepressure ratings, 100, 150,200, 261 psi, (6.9, 10.3, 13.8, 18 bar). The SUREX skidassembly flow rate capacity is selected based on the required flow rate per minuteof foam concentrate and percentage of foam injection required for all specialflammable liquid hazards.

The standard method of sizing the SUREX skidcapacity is by multiplying the area of the hazard by the required density,multiply that sum by the concentration of foam concentrate (1%, 2%, 3%),multiply that sum by a 1.15% safety factor for hydraulic over discharge andhydraulic balancing of the system piping. If the hazard required flow rate isknown, meaning the hydraulic calculations for the hazard have been performed,multiply the total water flow by the percent of foam to be used.

The SUREX skid assembly’s pressure ratingis selected after considering the pressure differential requirements of theILBP, (ILBP requires a minimum pressure differential of 15 psi (1 Bar)), addedto the static water pressure available at the riser. The pressure rating of theSUREX skid should be determined by adding in the pressure drop of theconcentrate discharge piping attributed to the length of the concentrate pipingfrom the SUREX skid discharge connection to the most remote ILBP. The typicalpressure rating of the system must exceed the residual water pressure to themost remote riser by 15 to 30 psi (1 to 2 Bar). You should select the nexthighest pressure rating pump.